Currently, applications, particularly some applications related to mobile Internet, such as instant messaging (IM), electronic mail (Email), and social network service (SNS), exist on a smartphone. An application on a terminal needs to communicate with an application server on a network side, and the application on the terminal keeps a network connection between the application and the application server effective in a long time in a manner of sending a piece of online information to the application server at intervals, namely, by using a heartbeat mechanism, thereby ensuring that when data is sent from the application server to the terminal, the data can reach the terminal accurately and in time. When no data is sent on a Packet Data Protocol (PDP) connection of the terminal in a period of time, to save power, the PDP connection is released, but when there is data to send, the PDP connection needs to be reestablished. Therefore, to send a heartbeat message, the terminal continuously performs a process of establishing and releasing the PDP connection, resulting in a signaling storm.
Currently, the industry proposes a push solution to solve the signaling storm problem. The core idea of the solution is to set a proxy server such as an always online architecture (AOI) server, a Push server or a services capability server (SCS) on a network side. A heartbeat message does not need to be kept between an application on a terminal and an application server, and the proxy server replaces the application to keep the heartbeat message between the application and the application server, thereby avoiding a process of continuously establishing and releasing a PDP connection of the terminal, and alleviating a network burden. However, when no data is sent from the terminal to the network side, the PDP connection is disconnected and no connection exists between the terminal and the proxy server. In this case, the proxy server cannot perceive whether the application is reachable, and therefore, an online state of the application reported by the proxy server to the application server may be incorrect.